Should we attend the civil wedding of a co-habiting couple?

[Maximus XVI]

hi, I have a friend whose sister (baptized Catholic) is going to be married to a boy (not Christian) with whom she has been living with (fornication) for 3 years. The wedding is going to be done by a "friend" of the groom, so its not even a Christian wedding, its more of just a civil union/marriage. My family was invited to this wedding. As devout Catholics, should we attend? Will their "marriage" be recognized by the Church? What message would our attendance (as faithful Catholics) say about our view on them living in a state of mortal sin for several years? Should we just politely decline the invitation? I don't know what to do. Please help.

Thanks.
God Bless

[Augusta Crowley]

The following link should assist you in better understanding on how to discern what weddings to attend and what weddings to avoid. If you have any further questions or concerns that are not answered by these links, please contact Catholic Answers directly.

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What are the rules for attending weddings?